Electric heating element



10, 1935. Q E. E. DRUMM 2,023,875

ELECTRIC HEATING ELEMENT Filed June 13, 1954 aszymla/ Patented Dec. 10, 1935 UNITED STATES PATENT OFFICE 9 Claims.

This invention pertains to electric heating elements of the wire resistance type, and has primarily for its object to provide an exceedingly simple, inexpensive, and eificient unit, in which the resistance coil is spaced from the base or support to prevent the accumulation of spilled food, or other substance, on the resistance, particularly where the same is employed in electric ranges, either toy or commercial.

Incidental to the foregoing, a more specific object of the inventionresides in the provision of an elongated arched support provided with at least one transverse insulating carrier projecting laterally from the support, and having the resistance wire secured to its ends in lateral spaced relation to the support, and above the plate or base by which the support is carried, the resistance being looped over an insulated supporting member cooperating with the transverse carrier to suspend the resistance substantially free of the support and base plate.

A further object resides in the provision of a heater of the foregoing character, in which a coiled or looped resistance is employed, the ends of the resistance being connected to the ends of a transverse insulating carrier, such as described, and having its intermediate portion looped over an insulating supporting hook, whereby assembly is materially facilitated, and the desired tension maintained upon the unsupported portions of the resistance to prevent sagging.

With the above and other objects in view which will appear as the description proceeds, the invention resides in the novel construction, combination, and arrangement of parts, substantially as hereinafter described and more particularly defined by the appended claims, it being understood that such changes in the precise embodiment of the herein disclosed invention may be made as come within the scope of the claims.

In the accompanying drawing is illustrated one complete example of the physical embodiment of the present invention constructed according to the best mode so far devised for the practical application of the principles thereof.

In the drawing:-

Figure 1 is a plan view of an element constructed in accordance with one form of the present invention.

Figure 2 is an elevation with parts broken away and in section to more clearly illustrate the structural features, and

Figure 3 is a detailed section taken on the line 3-3 of Figure 1.

While the present invention may have various applications, where a simple, inexpensive, electrical heating element is required, the same is more particularly designed for use in connection with toy electrical ranges, wherein the matter of cost is an important element in addition to that of 5 safety. With particular reference to the drawing, the numeral I designates a base plate, which may constitute either a permanent portion of an electric range, or may be suitably attached thereto in the oven of the range, or under the usual grill. Secured to the plate I is an elongated support 2 having an arched portion 3 spaced above the base plate I While the support may be secured to the base plate in various ways, one simple, inexpensive method is illustrated, in which one end of the support adjacent the arched portion 3 is provided with a foot 4 engaging the top of the plate I, and having spaced tongues 5 projecting through recesses 6 in the base plate and crimped back upon the plate to clamp the foot thereto. The opposite end of the support is provided with laterally projecting tongues 1, which also project through openings 8 in the base plate and are crimped back upon the same to lock the support thereto.

Secured to the arched portion 3 of the support 2 are a plurality of transverse carriers 9, preferably formed from insulating material, such as strips of mica, or similar non-conductive material, mica being preferred because of its cheapness. While these strips may be secured to the support 2 in any suitable manner, one simple, inexpensive means comprises the provision of punched out tongues l0 crimped over the edges of the carriers. As best shown in Figure 1, the carriers 9 project laterally beyond the side edges of the arched portion 3 of the support, and secured thereon adjacent their outer ends is a resistance element H, preferably of the conventional coiled wire type. The opposite ends of the resistance, which is in the form of a loop, are secured to terminal plates l2 riveted to the outer ends of the transverse carrier 9, the resistance wire being secured thereto by the crimped, staggered tongues 13 punched out of the terminal plates. Similar tongues I4 are provided in the opposite ends of the plates for receiving the feed lines ii.

In order to support the intermediate looped portion of the resistance ll, one end of the support 2 is provided with an upturned flange I 6 having an elongated vertical slot I l for reception of a hook l8, preferably formed of non-conductive material, thus eliminating necessity of insulating the hook from the flange I 6. Also in order to eliminate the necessity of attaching the hook IE to the flange I! by mechanical operation, the end of the hook is provided with lateral projections l9, which extend beyond the slot 11 and engage the flange.

Various means may be employed for attaching the side stretches of the resistance I I to the ends of the carriers 9, one simple form comprising the wire staples 20 passed through the coils of the resistance and crimped upon the ends of the carrier strips 9, thus avoiding mutilation of the coils of the resistance, and avoiding any obstruction of the same.

From the foregoing explanation, considered in connection with the accompanying drawing, it will be readily seen that an extremely simple, in-- expensive, and durable heating unitihas been pro.- vided, in which any particles of' food, or other substance, accidentally spilledupon the uniigwilli free themselves from the resistance, which is not only spaced from the support and base plate throughout" substantially its entire length, but is also fully insulatedto'prevent possibleshort circuiting.

Practically no mechanical operations are required in the assembly, other than crimpingv theparts together, and, aside from stamping and forming the various elements, no'machine operations are necessary. Assembly is further facilitated by the novel method ofattaching, the resistance to the end of. the carrier strips, and the novel means for supporting the looped portion, whereby the desired tension ismaintained upon the resistance element to prevent sagging and possible resulting contact with the base.

'While a plurality 'of' transverse-carriers have been illustrated, it is to'be understood that in instances where a comparatively short heating element is required, the purpose and advantages of the present invention can be accomplished with the use of. merely one transverse. carrier; incom-- bination with. the retaining hook for the intermediate portion of the resistance.

I claim:---

1. An electric heating unit comprising a long-itudinally extending, elongated, fiatsupport, atransversely'extending. carrier formed ofinsulating material secured to a. face-of said support and. projecting laterally from theopposite longitudinal edges of said support, alooped resistance element. having its opposite ends secured to the extended edges offlsaid carrier and spaced: laterally from the longi-tudinaledges of said support, and insulating means supporting the .intermediateportion of said resistance element illi spaced relation to said support.

2. An electrical heating unit comprising an elongated substantially flat support, a. carrier formed of. insulating material attached to one face of said support and projecting: laterally from the opposite longitudinal. edges thereof, a looped resilient resistance coil having its-opposite ends secured to the extended edges ofcsaid carrier and spaced laterally from said support, and means formed. of insulating material for supporting the intermediate portion of said resistance in:- spaced relation to said support and maintaining tension on the resistance.

3. An electrical: heating, unitcomprising an elongated substantially fiat support, 3/: transverse carrier strip formed from insulating material attached to one face of said supportandhaving its ends projecting beyond the opposite longitudinal edges of said support, a looped resistance coil having'its opposite ends secured to the ends of, said transverse strip to space the. resistance from V and its intermediate portions said support, and a hook formed of insulating ma longitudinal edges of the same, and a resistance element having its opposite ends secured to the extended ends of one of said transverse strips secured to the ends of the remaining strips at spaced intervals.

5. An electrical heating unit comprising an elongated substantially flat support, a plurality of transverse insulating strips attached to one faceof. said support and extending beyond the longitudinal edges of the same, a resistance element having its opposite ends secured to the extendeded'ges of one of said transverse strips and its: intermediate portions secured to the ends of" the remaining: strips at spaced intervals on one side of. the strips, and a hook formed of insulating material connected to said support and projecting beyond one face thereof for engagement with the central portion of said resistance.

6:, An electrical heating unit comprising a base plate, an elongated support attached to said base plateand provided with an arched portion, a plurality: of transverse insulating strips attached to said arched portionv and extending beyond the sides of the support, and a resistance coil having its:- opposite ends secured to the extended ends oi-one of said transverse strips and its intermediate'portion secured to the ends of the remaining strips at spaced; intervals.

7:..An electrical heating unit comprising an elongated substantially flat support, a transverse carrier strip formed from insulating material connected to one face of said support and having its ends projecting beyond the longitudinal edges of. said support, a looped resistance element having its opposite ends secured to the ends of said transverse strip to space the resistance fromsaid support, and a hook formed of insulating materialand having detachable interengagement with said support for supporting the intermediate.portion of said resistance.

8. An electrical heating element comprising a base plate, an elongated support attached to said base plate and provided with an arched portion, a plurality of transverse insulating strips attached to said arched portion and extending beyond the sides of the support, a looped resistface of said support and projecting laterally from the opposite longitudinal edges thereof, a looped resistance element having its opposite ends secured to the extended ends of one strip, and means for securing intermediate portions of the element to the extended ends of the other strips.

ELMER E. DRUMM. 

